Subsequently, mutations in the FGFR2, FGFR3, TWIST1, and EFNB1 genes have been shown to account for approximately 25% of craniosynostosis, whilst several additional genes make minor contributions.
Therefore, we have identified dimer partner selection as an important mediator of Twist1 function and provide a mechanistic understanding of craniosynostosis due to TWIST haploinsufficiency.
We therefore recommend that genetic analysis of the TWIST gene locus, including fluorescence in situ hybridization, should be considered in familial cases of facial and eyelid abnormalities without the presence of craniosynostosis.
Eyelid features were the hallmark of the disease for 12 members of the family, suggesting that mutations in TWIST may lead to a phenotype with mainly palpebral features and no craniostenosis.
We have now undertaken such a screen in 259 patients with craniosynostosis in whom mutations in other genes (e.g., FGFR1, FGFR3, and TWIST) had been excluded; part of this screen was a cohort-based study, enabling unbiased estimates of the mutation distribution to be obtained.
During a search for TWIST mutations in patients with craniosynostosis, we identified, in addition to 11 novel and one previously described bona fide mutations, several individuals with rearrangements of the glycine-rich region, involving either deletion of 18 nucleotides or insertion of three, 15, or 21 nucleotides.
Future TWIST mutational analysis on patients with craniosynostosis and radial ray involvement will shed light on whether Baller-Gerold syndrome should be a distinct entity or some cases should be reclassified as a heterogeneous form of SCS.
Mutations in the FGFR1-FGFR3 and TWIST genes are known to cause craniosynostosis, the former by constitutive activation and the latter by haploinsufficiency.
Mutations in the fibroblast growth factor receptor 1, 2 and 3 (FGFR1, -2 and -3) and TWIST genes have been identified in several syndromic forms of craniosynostosis.
Here the mutational screening of ten patients in the FGFR1, 2, and 3 genes and the TWIST gene causative of autosomal dominant craniosynostosis syndromes was reported.
Because Drosophila snail and twist are important regulators during mesoderm development and because human TWIST mutations have been implicated in craniosynostosis, a cohort of 59 patients with craniosynostosis syndromes were screened for SNAIL mutations.None were found.
Thirty-two unrelated patients with features of Saethre-Chotzen syndrome, a common autosomal dominant condition of craniosynostosis and limb anomalies, were screened for mutations in TWIST, FGFR2, and FGFR3.
Here, we report 21-bp insertions and nonsense mutations of the TWIST gene (S127X, E130X) in seven ACS III probands and describe impairment of head mesenchyme induction by TWIST as a novel pathophysiological mechanism in human craniosynostoses.